There will never be enough donor lungs available to meet current and future transplantation needs. In contrast, de-cellularization of whole cadaveric lungs will result in an intact scaffold that can be re-cellularized with embryonic stem cells or with adult stem cells, including induced pluripotent stem cells (iPS) derived from individual patients and subsequently utilized for autologous transplantation. Notably, the de-cellularization process removes cellular antigens responsible for immune rejection and the de-cellularized lungs maintain native airway and alveolar architecture, extracellular matrix protein composition, and pulmonary vascular network. This will provide a potentially limitless supply of unrelated donor cadaveric lungs for use in diseases such as emphysema and other diseases for which there is currently no effective cure. Our preliminary data demonstrates that de-cellularized mouse lungs can be re-cellularized with both adult and embryonic stem cells. Further, the de-cellularized lung preparations can be assessed by both histologic and functional outcomes including lung mechanics, surfactant production, vascular perfusion, and epithelial barrier function, as the lungs re-cellularize. Most importantly, preliminary data demonstrates that the lungs can be surgically re-implanted in animal models. These data provide a firm platform for the proposed multi-institutional collaborative studies in which state-of-the-art bioengineering techniques will be utilized to develop optimal methods for growing functional lung tissue in de-cellularized lungs, including cadaveric human lungs, and to devise optimal approaches for surgical implantation. The central goal of this proposal is therefore to utilize a comprehensive multidisciplinary multi- institutional approach for generation, functional characterization, and subsequent surgical implantation of viable lung tissue produced using stem cells in the de-cellularized lungs. This will be accomplished in the following two Specific Aims: 1) To optimize conditions for development of functional three dimensional lung tissue from embryonic and/or induced pluripotent stem cells grown in de-cellularized mouse lungs. 2) To develop strategies for successful in vivo implantation and functional assessment of re- cellularized lungs. PUBLIC HEALTH RELEVANCE: There will never be enough donor lungs available to meet current and future transplantation needs. In contrast, de-cellularization of whole cadaveric lungs will result in an intact scaffold that can be re-cellularized with stem cells (iPS) derived from individual patients and subsequently utilized for autologous transplantation. Our preliminary data demonstrates that de-cellularized mouse lungs can be re-cellularized with both adult and embryonic stem cells. The proposed multi-institutional collaborative studies will utilize state-of-the-art bioengineering techniques to develop optimal methods for growing functional lung tissue in de-cellularized lungs, including cadaveric human lungs, and to devise optimal approaches to surgically implant the re-cellularized lungs. This will provide a potentially limitless supply of unrelated donor cadaveric lungs for use in diseases such as emphysema, pulmonary fibrosis, and others for which there is currently no effective cure.